Controlling means for refrigerating apparatus



1936- G. H. WOODARD 2,050,516

CONTRQLLING MEANS FOR REFRIGERATING APPARATUS Filed March' 20, 1935 INVENTOR. 621m III iooolawol HISATTORNEY v Patented Aug. 11, 1936 UNITED STATES PATENT oFFIcE CONTROLLING MEANS FOR REFRIGER- ATING APPARATUS Application March 20, 1935, Serial No. 11,972

8 Claims.

This invention relates to improvements in refrigerating apparatus, and particularly to means for controlling the supply of the medium used as the refrigerant therein.

In refrigerating systems employing a liquid refrigerant, such as water, which is chilled by vaporizing part of the liquid in a closed vessel called the evaporator, the refrigerant after the temperature has thus been lowered is conducted away to a place where the refrigerating effect is desired and then returned to the evaporator to be cooled again. Systems of this sort are either open systems or closed systems. The former are of such a character that the refrigerant after it leaves the evaporator and before it is again admitted thereto passes through a receptacle or chamber in which the depth of the refrigerant may vary according to operating conditions. With this arrangement the quantity of the refrigerant on its way back to the evaporator can easily be regulated, so that filling of the evaporator and the attendant risk to other parts of the apparatus can readily be prevented. In the closed system, however, the chilled water is conducted through a sealed conduit to a closed'coil, in which it absorbs heat, and then it is returned to the evaporator through another sealed conduit.

The conduits and the cooling coil must be kept substantially filled when the apparatus is in operation, and if more refrigerant is present than is needed to fill these and not exceed a safe level in the evaporator, some means for removing the surplus is necessary.

It is an object of this invention to provide connections for disposing of the excess water in the so-called closed system and thus avoid flooding of the evaporator and possible damage to other members of the system.

In its preferred form the invention comprises a device adapted to be actuated in response to conditions in the evaporator and so coupled to the system that some of the refrigerant can be discharged therefrom whenever the quantity of circulating refrigerant becomes too large.

The objects and advantages of the invention are set out in the following description and the novel features are recited in the appended claims, but the disclosure is for purposes of illustration only and various changes without departing from the principle of the invention may be made in practice.

The drawing shows an outline of a system embodying this invention with part of the system shown in section.

The apparatus comprises an evaporator which is in the form of a closed vessel I to which the liquid refrigerant is supplied through an inlet pipe 2. This pipe projects into the evaporator and is provided therein with a number of openings through which the refrigerant is sprayed 5 downward in the form of jets. The evaporator has an outlet 3 at the top, to which is connected a suitable evacuating device (not shown) that creates and maintains a vacuum in the evaporator This vacuum is sufficiently high that 10 the water or other refrigerant entering by way of the pipe 2 will be vaporized in part, the portion which is converted into vapor extracting heat from the remainder of the liquid and thus lowering its temperature. The main body of the liquid is removed from the evaporator i through a discharge conduit 4 and transmitted therethrough to a coil 5 by a pump 6. This coil will e located at any point where a refrigerating effect is to be produced and the contents are of course warmed before they again reach the evaporator by way of the pipe 2.

As stated above, in a system of this kind where the water or the like flows through pipes and coils that are entirely closed from the time that it leaves the evaporator l until it is again admitted thereto, the water must necessarily be returned to the evaporator in the same quantity as it is delivered by the pump 6 to the coil 5. Hence, the water must be prevented from flooding the evaporator in case for any reason an excess of water arises. Besides the intake pipe 2, the evaporator is connected to a pipe I through which liquid refrigerant to make-up leakage and. other losses is supplied. The pipe I carries in the evaporator I a valve casing 9 containing a valve 8 and the lower end of this casing has an outlet ii]. The valve 8 may be a rotary valve with an outside arm II carrying a float I2. Whenever the level of the water in the evaporator l sinks, the float l2 will drop and open the valve 8 to replenish the water supply, and if the water level shows a tendency to rise in the evaporator the float l2 will be lifted and shut the valve 8. Thus the supply of the water or other refrigerant in the system is maintained, and any shortage is averted. But provision must also be made to prevent too much water from circulating in the system, thus filling the evaporator, and bringing about serious consequences to the evacuator connected to the outlet 3 if the water should rise and pass through this outlet. This evacuator will ordinarily be a centrifugal compressor and if water should rise high enough in the evaporator to enter the housing of the compressor, erosion of the vanes or worse damage could ensue. I therefore connect to the outlet pipe 4 beyond the pump 6 a branch pipe I3 which passes into and out of the evaporator, and the part inside the evaporator has a valve casing I4 in which there is a rotatable valve I5 having an outside arm I6 bearing a float IT. The other end of the pipe I3 is connected to a pipe I8 which may lead to the sewer or to a supply tank (not shown) for the pipe 7. If for any reason then there is an excess of water in the system, the rising level thereof will cause the float I! to rise and the valve I5 to open, whereupon some of the water which is taken out of the evaporator, instead of being passed to the coil 5, will be removed from the apparatus. Normally the float I! will be some distance above the operating level of the water so that the float will hold this valve closed by the weight thereof. But a rise in the level of the water suflicient to raise the float I"! will move the valve I5 to open position.

Hence in a closed system the requisite volume of water in the system will be maintained substantially constant, any excess will be quickly eliminated and any shortage quickly compensated. The system will always be kept full, but the water in the evaporator I can not rise to such height that it might pass through the outlet 3 and thus damage the evacuator. While this evacuator may be a centrifugal compressor, the invention is also useful when a different type of evacuator is utilized.

A one-way valve may be placed in the pipe 4 between the branch I3 and pump 6, and hand valves may also be inserted in the pipes 2, 4, I or I3 wherever they may be desired.

I claim.

1. The combination with a receptacle through which a liquid passes to be treated therein, of means actuated by the liquid in the receptacle to maintain a constant valume of liquid continuously and uninterruptedly undergoing treat ment therein, said means being arranged to effect addition of liquid to the receptacle when shortage of liquid occurs and subtraction of liquid from the receptacle when excess of liquid occurs.

2. The combination with an evaporator through which liquid refrigerant continuously passes and wherein said refrigerant is subjected to a vacuum to chill same, of control means actuated by the refrigerant in the evaporator to maintain a constant volume of liquid refrigerant therein, said means being arranged to effect addition of more liquid refrigerant to the evaporator when shortage of liquid occurs and subtraction .of liquid refrigerant when excess of liquid occurs and to effect said control without interrupting the chiliing process and without affecting the pressure in the evaporator.

3. In a refrigerating system, the combination of an evaporator to which a liquid refrigerant is admitted, liquid outlet means therefor, means to make up losses of said refrigerant, and means for removing an excess of said refrigerant from the system, said last-named means comprising a pipe connected to said liquid outlet means, and a valve actuated responsively to the level of the refrigerant in the evaporator to open and close said pipe.

4. In a refrigerating system, the combination of an evaporator to which a liquid refrigerant is admitted, means for making up losses of said refrigerant, said evaporator having an outlet and a pump to deliver said refrigerant to a cooling coil, a pipe connected to said outlet beyond said pump, part of said pipe being within the evaporator, a valve in said pipe, and a float in the evaporator to open said valve when the refrigerant in the evaporator reaches a prede-- termined level.

5. The combination with a closed-cycle refrigerating system through which liquid refrigerant circulates, of means for effecting addition of refrigerant to the system when shortage of liquid occurs and subtraction of refrigerant from the system when excess of liquid occurs, the said means being actuated by the refrigerant in the system to continuously maintain a definite volun'ie of refrigerant therein.

6. In combination with an evaporator chamber, a closed-cycle refrigerating system through which liquid refrigerant circulates, means for adding new refrigerant to the system, and means for subtracting refrigerant from the system, each of said means being independently responsive to refrigerant level in said chamber to continuously maintain a definite volume of refrigerant in the system.

7. The combination with a closed-cycle refrigerating system through which liquid refrigerant circulates and comprising in series an evaporator chamber, discharge means therefor, means whereby the refrigerating effect is utilized, and inlet means to reintroduce refrigerant to said chamber, of control means responsive to refrigerant level in said chamber to continuously maintain a definite volume of refrigerant in said system by effecting addition of refrigerant to said system Whenever shortage occurs therein and subtraction of refrigerant from said system whenever excess occurs therein.

8. Refrigerating apparatus and control means according to claim '7 wherein the said control means comprises two float actuated valves, one to effect the addition of liquid refrigerant and the other to effect the subtraction of liquid refrigerant.

GEORGE H. WOODARD. 

